Maternal iodine deficiency during pregnancy is associated with inadequate language development, lower fine motor skills and presence of behavioral problems amongst the children by the age of three.
These insights are from the Norwegian Mother and Child Cohort Study (MoBa), which emphasizes the role of iodine in producing adequate thyroid hormone that is crucial for the development of the fetus’s brain.
Iodine Deficiency Disorders
Iodine is very important and essential in proper synthesis of thyroid hormones which affects growth and development of the individual including the brain and the central nervous system.
Iodine deficiency is one of the greatest threats to public health everywhere around the world especially among pregnant women and elderly, with serious and often irreversible consequences for the development of the fetus.
According to the World health organization (who), world wide, there has been a target set to eliminate deprivation of iodine and thus salt iodization has been used as a means to eradicate iodine deficiency disorders.
Key Findings
Developmental Issues Due to Iodine Deficiency During Pregnancy
Iodine deficiency during pregnancy is linked to key developmental milestones in children. The MoBa study yielded results that clearly showed low iodine intake during pregnancy to be hazardous by way of some key developmental milestones in children. These included language, ability of children to use their hands, and behavior by age three. However, there was no such recommendation to gross sills children and the age at which they ascended to their feet.
Prevalence of Iodine Deficiency
From the pregnancy issue recall of a 24 hour food recall more quantitative data relating to and alarming statistics were observed:
- 63% of women were found to have insufficient iodine intake, consuming an average of 175 μg/day, which is below the recommended intake level.
- Another 17% were found to have consumed iodine intake of less than half the inspiration dose.
Lack of Protection from Supplements
The study also sought to assess whether iodine containing supplements may decrease adverse effects of low iodine intake. The result however indicated that it may be too late to start iodine supplementation since its introduction in pregnancy may have no further positive impact on child development.
Epidemiology of Iodine Deficiency
Iodine deficiency is a common concern as over 2 billion human beings suffer from this globally. Attending to the report from WHO, there are 12 countries that have excessive iodine intake, 116 country’s population is providing adequate iodine nutrition, and 25 populations are still endemic in iodine deficiency.
In Europe, mild to moderate iodine deficiency are fairly common, affecting over 350 million people. The median urinary iodine concentration (UIC) is used to ascertain iodine intake status of individuals and populations and is endorsed by the WHO for this purpose. Population is said to be categorized as having a severe iodine deficiency when median UIC of school children is less than 20 μg/L.
The Role of Thyroid Hormones in Fetal Brain Development
Thyroid hormones play a critical role in fetal brain development, and iodine is essential for the production of these hormones. Maternal thyroid hormones are found in the embryonic cavities around four weeks after conception, and thyroid hormones are not believed to play a role in very early fetal development.
A 50% increase in iodine intake is recommended for pregnant women to produce enough thyroid hormones to meet fetal requirements. A lack of iodine in the diet may result in the mother becoming iodine deficient, and subsequently the fetus. The mother and the fetus respond differently to iodine deficiency, with the mother remaining euthyroid and the fetus becoming hypothyroid.
Localized hypothyroxinemia occurring in specific parts of the developing fetal brain is believed to be responsible for the neurodevelopmental damage seen in iodine deficiency.
Implications for Child Development
The consequences of low iodine levels may be insidious to every single child; however, the situation of iodine deficit intake among pregnant women in Norway is distressing.
The researchers suppose that if these results are truly causal, even mild iodine deficiency might cause language delays, behavioral issues, and other developmental problems in Norwegian children within three years.
The Need for Further Research
The study agrees with other findings, but the authors point to the need for further studies in order to establish causality between the lack of iodine and certain developmental outcomes in children. Specifically, further research is needed to understand the impact of maternal iodine supplementation on child development. The MoBa study is well-placed to study such associations given the large sample size and thorough nature of the data.
In the future, researchers intend to look at additional potential brain development outcomes of the children, such as the likely heightened risk of attention deficit hyperactivity disorder, as they become older.
Urgent Call for Action
The findings of this study seem to support what was included in the 2016 report by the Norwegian Nutrition Council which makes emphatic recommendations regarding the necessary steps to guarantee adequate iodine consumption by pregnant women.
In addition, it is crucial that women consume sufficient iodine for some period of time prior to conception since supplementation in pregnancy might also not be enough for such pre-existing deficiency conditions. One of the most common ways to prevent such mineral deficiencies is the iodized salt utilization which in turn prevents positive humidity in pregnant women and the general populace.
Universal salt iodization has been recognized as one of the important measures that can be implemented across countries to address iodine deficiency disorders and improve the health status of the population.
Conclusion
Monitoring iodine status is crucial for ensuring proper neurodevelopment in children. Pregnant women must consume enough iodine for the proper neurodevelopment of their children. This study highlights the need to tackle iodine deficiency before conception so as to avoid any expected delays in development or behavioral changes in children.
Journal Reference
The study, titled "Suboptimal Maternal Iodine Intake Is Associated with Impaired Child Neurodevelopment at 3 Years of Age in the Norwegian Mother and Child Cohort Study," was published in The Journal of Nutrition.
For more information, visit the Journal of Nutrition or refer to the Norwegian Institute of Public Health’s publications on iodine deficiency.
